In climates that do not provide sufficient rainfall, irrigation is required to maintain the health and the appearance of the landscape. Automated sprinkler systems are commonly installed in residential and commercial properties to provide sufficient irrigation in a manner that conserves water. An automated sprinkler system typically draws water from a water supply and distributes it through a number of sprinkler heads or other water dispersing devices. The water used by a sprinkler system may be drawn from a water district that provides potable water to a community or a private well system that provides potable water to a property.
Various state laws and local regulations govern measures that must be taken to protect the water supply from which water is drawn. For example, the Texas Commission on Environmental Quality requires that sprinkler systems connect to the water supply through backflow prevention assemblies that prevent water from flowing back to the water supply (backsiphonage). In a sprinkler system, a backflow prevention assembly prevents stagnant water from the sprinkler system from being drawn back into the potable water supply to protect it from contamination.
A backflow prevention assembly typically includes an inlet shutoff valve, a backflow preventer, and an outlet shutoff valve and any piping that may fluidly connect them. The backflow preventer is typically required to be installed above ground, at least 12 inches above the highest point of the sprinkler system and installed vertically with respect to the pipe through which water is drawn. Commercially available backflow preventers and backflow prevention assemblies that are commonly used in sprinkler systems include those manufactured by Febco®, Apollo®, and Zurn®.